Display device and electronic apparatus

ABSTRACT

A display device includes a plurality of signal lines that are so juxtaposed as to be extended along one direction, a plurality of common drive electrodes that are so juxtaposed as to be extended along the signal lines, and a plurality of display elements that are each connected to a respective one of the plurality of signal lines and are each connected also to the common drive electrode that makes a pair with the connected signal line. Scan driving of the plurality of display elements is performed in the direction of the signal lines.

BACKGROUND

The present disclosure relates to display devices, and particularly to adisplay device configured with a liquid crystal display element andelectronic apparatus including such a display device.

In recent years, the liquid crystal display device has become themainstream of the display device in terms of low power consumption andspace saving. Some liquid crystal display devices include a commonelectrode that gives a common potential to plural pixels and a pixelelectrode that is so provided for each pixel as to be opposed to thecommon electrode with the intermediary of a liquid crystal layer, forexample. In such a liquid crystal display device, for example, inversiondriving is performed by applying a pixel signal to the pixel electrodeand applying a rectangular wave signal to the common electrode, anddisplaying is performed by changing the orientation of liquid crystalmolecules based on the difference between the potential of the pixelelectrode and the potential of the common electrode (pixel potential).

In some of the liquid crystal display devices, ingenuity is exercised onthe common electrode. For example, Japanese Patent Laid-open No.2009-251608 proposes a liquid crystal display device including pluralcommon electrodes that are extended along the row direction of thedisplay surface and juxtaposed in the column direction. In this liquidcrystal display device, e.g. in the case of applying a drive signal tothe common electrode in order to perform inversion driving, the drivesignal is applied only to the common electrode relating to the pixels inone horizontal line in which the pixel signal is written. This allowsreduction in the power consumption in the driving of the commonelectrode.

SUMMARY

The common electrode generally should have optical transparency and isoften formed by using indium tin oxide (ITO). Such a common electrodehas higher resistance and larger time constant compared with the case ofusing a metal such as aluminum. In this case, in writing of the pixelsignal to pixels, this pixel signal travels to the common electrode andwriting to adjacent pixels in the same one horizontal line is disturbed,so that possibly the image quality is deteriorated due to thiscrosstalk.

Furthermore, the drive circuit to drive the common electrode is desiredto perform driving with low output impedance for the common electrode.However, depending on the arrangement of this drive circuit, its outputimpedance becomes high because of e.g. a long length of a power supplyline to this drive circuit, and thus possibly driving the commonelectrode becomes difficult and the image quality is deteriorated.

There is a need for a technique to provide a display device andelectronic apparatus capable of suppressing the deterioration of theimage quality attribute to the common electrode.

According to an embodiment of the present disclosure, there is provideda display device including a plurality of signal lines, a plurality ofcommon drive electrodes, and a plurality of display elements. Theplurality of signal lines are so juxtaposed as to be extended along onedirection. The plurality of common drive electrodes are so juxtaposed asto be extended along the signal lines. The plurality of display elementsare each connected to a respective one of the plurality of signal linesand are each connected also to the common drive electrode that makes apair with the connected signal line. Scan driving of the plurality ofdisplay elements is performed in the direction of the signal lines.

According to another embodiment of the present disclosure, there isprovided electronic apparatus including the above-described displaydevice. Examples of the electronic apparatus include a televisiondevice, a digital camera, a personal computer, a video camcorder, and aportable terminal device typified by a cellular phone.

In the display device and the electronic apparatus of the embodiments ofthe present disclosure, scan driving of the display elements isperformed in the direction of the signal lines. In this scan driving, tothe plural display elements simultaneously driven, a signal forperforming displaying is supplied from each of the signal line and thecommon drive electrode, which are extended along the same direction,separately.

According to further embodiment of the present disclosure, there isprovided a display device including a plurality of signal linesconfigured to be so juxtaposed as to be extended along a firstdirection, a plurality of drive electrodes configured to be sojuxtaposed as to be extended along the first direction, and a pluralityof display elements configured to be subjected to scan driving in thefirst direction.

According to the display device and the electronic apparatus of theembodiments of the present disclosure, the common drive electrodes areso disposed as to be extended along the signal lines and displaying isperformed by scan driving in the direction of the signal lines. Thus,the deterioration of the image quality attributed to the commonelectrode can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing one configuration example of a displaydevice according to an embodiment of the present disclosure;

FIG. 2 is a block diagram showing one configuration example of aselection switch unit shown in FIG. 1;

FIG. 3 is a sectional view showing the schematic sectional structure ofa display unit shown in FIG. 1;

FIG. 4 is a circuit diagram showing one configuration example of thedisplay unit shown in FIG. 1;

FIG. 5 is an explanatory diagram showing one configuration example of adrive electrode shown in FIG. 4;

FIGS. 6A and 6B are schematic diagrams showing examples of mounting ofthe display device shown in FIG. 1 into a module;

FIGS. 7A to 7E are timing waveform diagrams showing one operationexample of the display device shown in FIG. 1;

FIGS. 8A and 8B are schematic diagrams showing one operation example ofthe display device shown in FIG. 1;

FIGS. 9A and 9B are circuit diagrams for explaining the operation of thedisplay device shown in FIG. 1;

FIG. 10 is a circuit diagram showing one configuration example of thedisplay unit according to a comparative example;

FIG. 11 is a schematic diagram showing an example of mounting of thedisplay device according to the comparative example into a module;

FIGS. 12A to 12D are timing waveform diagrams showing one operationexample of the display device according to the comparative example;

FIGS. 13A and 13B are circuit diagrams for explaining the operation ofthe display device according to the comparative example;

FIGS. 14A and 14B are characteristic diagrams showing characteristics ofthe display devices according to the embodiment and the comparativeexample;

FIG. 15 is an explanatory diagram showing one configuration example ofthe drive electrode according to a modification example;

FIGS. 16A and 16B are explanatory diagrams showing one configurationexample of the drive electrode according to another modificationexample;

FIG. 17 is an explanatory diagram showing one configuration example ofthe drive electrode according to another modification example;

FIGS. 18A and 18B are schematic diagrams showing one operation exampleof the display device according to another modification example;

FIG. 19 is a perspective view showing the appearance configuration ofapplication example 1 of pieces of electronic apparatus to which theembodiment is applied;

FIGS. 20A 20B are perspective views showing the appearance configurationof application example 2;

FIG. 21 is a perspective view showing the appearance configuration ofapplication example 3,

FIG. 22 is a perspective view showing the appearance configuration ofapplication example 4;

FIGS. 23A to 23G are front view, side view, top view, and bottom viewshowing the appearance configuration of application example 5; and

FIG. 24 is a sectional view showing the schematic sectional structure ofthe display unit according to another modification example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present disclosure will be described in detailbelow with reference to the drawings. The order of the description is asfollows.

-   1. Embodiment-   2. Application Examples

<1. EMBODIMENT> [Configuration Example] (Overall Configuration Example)

FIG. 1 shows one configuration example of a display device according toan embodiment of the present disclosure. A display device 1 is a liquidcrystal display device configured with use of a liquid crystal displayelement as a display element. The display device 1 includes a controller11, a gate driver 12, a source driver 13, a selection switch unit 14, adrive signal generator 15, a drive electrode driver 16, and a displayunit 20.

The controller 11 is a circuit that supplies a control signal to each ofthe gate driver 12, the source driver 13, the drive signal generator 15,and the drive electrode driver 16 based on a video signal Vdisp suppliedfrom the external and controls them so that they may operate insynchronization with each other. Specifically, the controller 11supplies a display scan timing control signal to the gate driver 12 andsupplies a video signal and a display timing control signal to thesource driver 13. In addition, the controller 11 supplies a drive signaltiming control signal to the drive signal generator 15 and the driveelectrode driver 16.

The gate driver 12 has a function to sequentially select one horizontalline as the subject of display driving of the display unit 20 based onthe control signal supplied from the controller 11. Specifically, asdescribed later, the gate driver 12 applies a scan signal Vscan to thegates of TFT elements Tr in pixels Pix via a scan signal line GCL tothereby sequentially select one row (one horizontal line) of the pixelsPix formed in a matrix manner in the display unit 20 as the subject ofdisplay driving.

The source driver 13 generates and outputs a pixel signal Vsig based onthe video signal and the control signal supplied from the controller 11.Specifically, as described later, the source driver 13 generates, fromthe video signal for one horizontal line, the pixel signal Vsig obtainedby time-division multiplexing of pixel signals Vpix of plural (in thisexample, three) sub-pixels SPix of the display unit 20 and supplies thepixel signal Vsig to the selection switch unit 14. Furthermore, thesource driver 13 generates switch control signals VselR, VselG, andVselB used to separate the pixel signals Vpix multiplexed into the pixelsignal Vsig and supplies these signals to the selection switch unit 14together with the pixel signal Vsig. This multiplexing is carried out toreduce the number of interconnects between the source driver 13 and theselection switch unit 14.

The selection switch unit 14 separates the pixel signals Vpix subjectedto the time-division multiplexing into the pixel signal Vsig based onthe pixel signal Vsig and the switch control signals VselR, VselG, andVselB supplied from the source driver 13, and supplies the pixel signalsVpix to the display unit 20.

FIG. 2 shows one configuration example of the selection switch unit 14.The selection switch unit 14 has plural switch groups 17. In thisexample, each switch group 17 is composed of three switches SWR, SWG,and SWB. One terminals of these switches are connected to each other andsupplied with the pixel signal Vsig from the source driver 13, and theother terminals are each connected to a respective one of the sub-pixelsSPix corresponding to red (R), green (G), and blue (B) via a pixelsignal line SGL of the display unit 20. These three switches SWR, SWG,and SWB are on/off-controlled by the switch control signals VselR,VselG, and VselB supplied from the source driver 13. Based on thisconfiguration, the selection switch unit 14 sequentially turns thesethree switches to the on-state in a time-division manner in response tothe switch control signals VselR, VselG, and VselB to thereby functionto separate the pixel signals Vpix (VpixR, VpixG, VpixB) from the pixelsignal Vsig obtained by multiplexing. Furthermore, the selection switchunit 14 supplies these pixel signals Vpix to three sub-pixels SPix.

The drive signal generator 15 generates a drive signal Vcom with analternate current (AC) rectangular waveform based on the control signalsupplied from the controller 11 and supplies it to the drive electrodedriver 16.

The drive electrode driver 16 is a circuit that supplies the drivesignal Vcom to drive electrodes COML (described later) of the displayunit 20 based on the control signal supplied from the controller 11.Specifically, the drive electrode driver 16 applies the drive signalsVcom having AC rectangular waveforms with polarities opposite to eachother to the drive electrodes COML adjacent to each other as describedlater. In association with this, the pixel signals Vpix with polaritiesopposite to each other are applied to the sub-pixels SPix adjacent toeach other. That is, in this example, the display unit 20 is driven byso-called dot-inversion driving (sub-pixel-inversion driving).

The display unit 20 is configured with use of the liquid crystal displayelement and performs displaying through sequential scanning of each onehorizontal line based on the pixel signal Vpix, the scan signal Vscan,and the drive signal Vcom as described later.

FIG. 3 shows an example of the sectional structure of the major part ofthe display unit 20. This display unit 20 includes a pixel substrate 2,a counter substrate 3 disposed opposed to this pixel substrate 2, and aliquid crystal layer 6 interposed between the pixel substrate 2 and thecounter substrate 3.

The pixel substrate 2 has a TFT substrate 21 as a circuit board andplural pixel electrodes 22 arranged in a matrix on this TFT substrate21. On the TFT substrate 21, thin film transistors (TFT) of therespective pixels and interconnects such as the pixel signal line SGL tosupply the pikel signal Vpix to each pixel electrode 22 and the scansignal line GCL to drive each TFT are formed although not shown in thedrawing.

The counter substrate 3 has a glass substrate 31, a color filter 32formed on one surface of this glass substrate 31, and the plural driveelectrodes COML formed on this color filter 32. The color filter 32 isconfigured by periodically arranging color filter layers of e.g. threecolors of red (R), green (G), and blue (B) and three colors of R, G, andB are associated with each display pixel as one set. The drive electrodeCOML functions as the common drive electrode of the display unit 20. Thedrive electrode COML is coupled to the TFT substrate 21 by a contactelectrically-conductive pillar (not shown) and the drive signal Vcomhaving an AC rectangular waveform is applied from the TFT substrate 21to the drive electrode COML via this contact electrically-conductivepillar. A polarizer 35 is disposed on the other surface of the glasssubstrate 31.

The liquid crystal layer 6 modulates light passing through it dependingon the state of an electric field. For example, a liquid crystal of anyof various modes such as twisted nematic (TN), vertical alignment (VA),and electrically controlled birefringence (ECB) modes is used.

An alignment film is provided between the liquid crystal layer 6 and thepixel substrate 2 and between the liquid crystal layer 6 and the countersubstrate 3, and an incidence-side polarizer is disposed on the lowersurface side of the pixel substrate 2. In FIG. 3, diagrammaticrepresentation of these components is omitted.

FIG. 4 shows a configuration example of the pixel structure in thedisplay unit 20. The display unit 20 has the plural pixels Pix arrangedin a matrix. Each pixel Pix is composed of three sub-pixels SPix. Thesethree sub-pixels SPix are so disposed as to each correspond to arespective one of three colors (RGB) of the color filter 32 shown inFIG. 3. The sub-pixel SPix has the TFT element Tr, a liquid crystalelement LC, and a holding capacitance element Cs. The TFT element Tr isformed of a thin film transistor. In this example, it is formed of ann-channel metal oxide semiconductor (MOS) TFT. The source of the TFTelement Tr is connected to the pixel signal line SGL. The gate isconnected to the scan signal line GCL and the drain is connected to oneterminal of the liquid crystal element LC. One terminal of the liquidcrystal element LC is connected to the drain of the TFT element Tr andthe other terminal is connected to the drive electrode COML. The holdingcapacitance element Cs is to hold the potential difference across theliquid crystal element LC. One terminal thereof is connected to thedrain of the TFT element Tr and the other terminal is connected to thedrive electrode COML.

The sub-pixel SPix is connected to the other sub-pixels SPix that belongto the same row of the display unit 20 by the scan signal line GCL. Thescan signal line GCL is connected to the gate driver 12 and suppliedwith the scan signal Vscan by the gate driver 12. Furthermore, thesub-pixel SPix is connected to the other sub-pixels SPix that belong tothe same column of the display unit 20 by the pixel signal line SGL. Thepixel signal line SGL is connected to the selection switch unit 14 andsupplied with the pixel signal Vpix by the selection switch unit 14.

Moreover, the sub-pixel SPix is connected to the other sub-pixels SPixthat belong to the same column of the display unit 20 by the driveelectrode COML. The drive electrode COML is connected to the driveelectrode driver 16 and supplied with the drive signal Vcom by the driveelectrode driver 16.

FIG. 5 shows one configuration example of the drive electrode COML. Inthis example, the drive electrodes COML are so formed as to be extendedalong the same direction as that of the pixel signal lines SGL, and theplural sub-pixels SPix that belong to the same one column share onedrive electrode COML. Each drive electrode COML is connected to thedrive electrode driver 16 via a drive electrode line part 29. That is,the drive electrode driver 16 supplies the drive signal Vcom in units ofthe sub-pixel SPix.

Based on this configuration, in the display unit 20, the gate driver 12drives the scan signal lines GCL in such a manner as toline-sequentially scan them in a time-division manner and thereby onehorizontal line is sequentially selected. In addition, the selectionswitch unit 14 supplies the pixel signal Vpix to the pixels Pix thatbelong to this one horizontal line and thereby displaying is performedon each one horizontal line basis.

FIGS. 6A and 6B schematically show mounting of the display device 1 intoa display module: FIG. 6A shows one example of the mounting and FIG. 6Bshows another example.

A display module 5A shown in FIG. 6A has the display unit 20, a chip onglass (COG) 19, gate drivers 12A and 12B, and the selection switch unit14. As schematically shown in FIG. 6A, in the display unit 20, the driveelectrodes COML are so formed as to be extended along the same directionas that of the pixel signal lines SGL. The COG 19 is a chip mounted onthe TFT substrate 21 and includes the respective circuits used fordisplay operation, such as the controller 11, the source driver 13, thedrive signal generator 15, and the drive electrode driver 16 shown inFIG. 1. The gate drivers 12A and 12B are equivalent to the gate driver12 shown in FIG. 1 and are so configured as to apply the scan signalVscan to the scan signal line SGL from both sides of the display unit20. The gate drivers 12A and 12B and the selection switch unit 14 areformed on the TFT substrate 21, which is a glass substrate.

A display module 5B shown in FIG. 6B includes a drive electrode driver16B on the opposite side to a terminal part T of the display unit 20.This drive electrode driver 16B is provided to assist the driveelectrode driver 16 included in the COG 19. Based on this configuration,in the display module 5B, the drive electrode driver 16 in the COG 19and the drive electrode driver 16B apply the drive signal Vcom to thedrive electrode COML from both sides of the display unit 20.

As shown in FIGS. 6A and 6B, the drive electrodes COML are connected tothe COG 19 including the drive electrode driver 16 across a shortdistance. The drive electrode driver 16 is formed in the same COG 19 asthat of the drive signal generator 15, which generates the drive signalVcom. The COG 19 is disposed at a position near the terminal part T tosupply the power of the COG 19. This allows the drive electrode driver16 to drive the drive electrodes COML with low output impedance.

The pixel signal line SGL is equivalent to one specific example of the“signal line” in the present disclosure. The drive electrode COML isequivalent to one specific example of the “common drive electrode” inthe present disclosure. The liquid crystal element LC is equivalent toone specific example of the “display element” in the present disclosure.The drive electrode driver 16 is equivalent to one specific example ofthe “driver” in the present disclosure.

[Operation and Effect]

The operation and effect of the display device 1 of the presentembodiment will be described below.

(Outline of Overall Operation)

The controller 11 supplies the control signal to each of the gate driver12, the source driver 13, the drive signal generator 15, and the driveelectrode driver 16 based on the video signal Vdisp supplied from theexternal and controls them so that they may operate in synchronizationwith each other. The gate driver 12 generates the scan signal Vscan andsupplies it to the display unit 20. The source driver 13 generates thepixel signal Vsig obtained by multiplexing of the pixel signals Vpix andthe switch control signals VselR, VselG, and VselB corresponding to thepixel signal Vsig and supplies these signals to the selection switchunit 14. The selection switch unit 14 generates the pixel signals Vpixby separation based on the pixel signal Vsig and the switch controlsignals VselR, VselG, and VselB and supplies them to the display unit20. The drive signal generator 15 generates the drive signal Vcom andsupplies it to the drive electrode driver 16. The drive electrode driver16 applies the drive signal Vcom to the drive electrode COML of thedisplay unit 20. The display unit 20 performs line-sequential scanningon each one horizontal line basis based on the supplied pixel signalVpix, scan signal Vscan, and drive signal Vcom to thereby display theimage corresponding to the video signal Vdisp.

(Detailed Operation)

The detailed operation of the display device 1 will be described belowwith use of several diagrams.

FIGS. 7A to 7E show timing waveform examples of the display device 1.Specifically, FIG. 7A shows the waveform of the drive signal Vcom. FIG.7B shows the waveform of the scan signal Vscan. FIG. 7C shows thewaveform of the pixel signal Vsig. FIG. 7D shows the waveforms of theswitch control signals VselR, VselG, and VselB. FIG. 7E shows thewaveforms of the pixel signals VpixR, VpixG, and VpixB.

The display device 1 carries out display operation by dot-inversiondriving (sub-pixel-inversion driving) based on the drive signal Vcom,the scan signal Vscan, and the pixel signal Vsig. Details of theoperation will be described below.

First, at timing t1, the drive signal generator 15 inverts the drivesignal Vcom and the drive electrode driver 16 applies this drive signalVcom to the drive electrode COML (FIG. 7A).

Next, at timing t2, the gate driver 12 applies the scan signal Vscan(n)to the scan signal line GCL for the pixels Pix on the n-th row and thescan signal Vscan(n) changes from the low level to the high level (FIG.7B). Thereby, the TFT elements Tr of the pixels Pix on the n-th rowbecome the on-state and one horizontal line in which writing operationis carried out in the display unit 20 is selected.

Next, the source driver 13 outputs the pixel signal Vsig and the switchcontrol signals VselR, VselG, and VselB. Specifically, first, at timingt3, the source driver 13 outputs a voltage VR for the sub-pixel SPix ofred (R) (FIG. 7C) and changes the switch control signal VselR from thelow level to the high level (FIG. 7D). At this time, the switch SWR ineach of the switch groups 17 of the selection switch unit 14 becomes theon-state and the pixel signal VpixR (voltage VR) is supplied to thepixel signal line SGL connected to the switch SWR (FIG. 7E). Thereafter,when the switch control signal VselR changes from the high level to thelow level, the switch SWR becomes the off-state and the pixel signalline SGL connected to the switch SWR becomes the floating state. Thus,the pixel signal VpixR is kept. Similarly, at timing t4, the sourcedriver 13 outputs a voltage VG for the sub-pixel SPix of green (G) (FIG.7C) and changes the switch control signal VselG from the low level tothe high level (FIG. 7D) to thereby supply the pixel signal VpixG(voltage VG) to the pixel signal line SGL connected to the switch SWG(FIG. 7E). Subsequently, at timing t5, the source driver 13 outputs avoltage VB for the sub-pixel SPix of blue (B) (FIG. 7C) and changes theswitch control signal VselB from the low level to the high level (FIG.7D) to thereby supply the pixel signal VpixB (voltage VB) to the pixelsignal line SGL connected to the switch SWB (FIG. 7E).

In the pixels Pix in one horizontal line, the pixel signals Vpix (VpixR,VpixG, VpixB) are supplied via the pixel signal lines SGL in theabove-described manner and thereby writing is performed.

Thereafter, at timing t6, the gate driver 12 changes the scan signalVscan(n) from the high level to the low level (FIG. 7B). Thereby, theTFT elements Tr of the pixels Vpix on the n-th row become the off-state,so that the writing operation is ended.

From then on, by repeating the above-described operation, the displaydevice 1 carries out the writing operation for the whole displaysurface.

FIGS. 8A and 8B schematically show the dot-inversion driving.Specifically, FIG. 8A shows the polarities of the pixel potentials forthe sub-pixels SPix in a certain frame. FIG. 8B show the polarities ofthe pixel potentials in the next frame. The pixel potential refers tothe potential difference between the pixel signal Vpix and the drivesignal Vcom in the sub-pixel SPix. As shown in FIGS. 8A and 8B, in thedot-inversion driving, driving is performed in such a manner that thepolarities of the pixel potentials of the sub-pixels SPix adjacent toeach other are different from each other in a certain frame.Furthermore, the polarities of the pixel potentials of all of thesub-pixels SPix are inverted on a frame-by-frame basis.

In this dot-inversion driving, the drive electrode driver 16 applies thedrive signals Vcom having AC rectangular waveforms with polaritiesopposite to each other to the drive electrodes COML adjacent to eachother. Furthermore, in association with this operation of the driveelectrode driver 16, the source driver 13 and the selection switch unit14 apply the pixel signals Vpix with polarities opposite to each otherto the pixel signal lines SGL adjacent to each other.

In this manner, in the display device 1, the drive signal Vcom issupplied from each of the different drive electrodes COML to arespective one of the sub-pixels SPix in one horizontal line that isselected by the scan signal Vscan and in which the pixel signal Vpix iswritten. That is, in the writing operation, the drive signal Vcom isindependently supplied to each of the sub-pixels SPix in this onehorizontal line. This can reduce the possibility that noise is mixedfrom the other sub-pixels SPix in this one horizontal line via the driveelectrode COML.

Next, the load of the drive electrode driver 16 will be described below.

FIGS. 9A and 9B show the equivalent circuit of the display unit 20.Specifically, FIG. 9A shows the case in which the TFT elements Tr are inthe off-state. FIG. 9B shows the case in which the TFT elements Tr arein the on-state. A capacitive element Clc is an equivalent element whenthe liquid crystal element LC is regarded as a capacitive element.

When the scan signal Vscan at the low level is applied to the scansignal line GCL and the TFT element Tr is in the off-state, the TFTelement Tr can be replaced by a capacitive element Cds corresponding tothe parasitic capacitance between the drain and the source as shown inFIG. 9A. At this time, the load from the viewpoint of the driveelectrode COML in each sub-pixel SPix is series capacitance made withparallel capacitance (Clc+Cs) of the capacitive elements Clc and Cs andthe capacitive element Cds. In general, the capacitance Cds issufficiently lower than the capacitance (Clc+Cs) and therefore thisseries capacitance is almost equal to the capacitance Cds. That is, theload from the viewpoint of the drive electrode COML in the sub-pixelSPix in which the TFT element Tr is in the off-state is a lightcapacitive load.

On the other hand, when the scan signal Vscan at the high level isapplied to the scan signal line GCL and the TFT element Tr is in theon-state, the TFT element Tr can be replaced by a resistive element Roncorresponding to the on-resistance between the drain and the source asshown in FIG. 9B. In general, this on-resistance is sufficiently low andtherefore the capacitance (Clc+Cs) is dominant in the load from theviewpoint of the drive electrode COML in each sub-pixel SPix. That is,the load from the viewpoint of the drive electrode COML in the sub-pixelSPix in which the TFT element Tr is in the on-state is a heavycapacitive load.

In the display device 1, always writing is performed in only onesub-pixel SPix of the sub-pixels SPix connected to a respective one ofthe drive electrodes COML. That is, the total load from the viewpoint ofthe drive electrode COML in the display unit 20 is the sum of the heavycapacitive load of the sub-pixel SPix in one horizontal line as thewriting subject and the light capacitive loads of the other sub-pixelsSPix. That is, the sub-pixel SPix with the heavy capacitive load is onlyone sub-pixel for each drive electrode COML. This makes it easier forthe drive electrode driver 16 to drive the drive electrodes COML.

Comparison with Comparative Example

The effect of the present embodiment will be described below based oncomparison with a comparative example.

First, a display device 1R according to the comparative example will bedescribed. In the present embodiment (FIG. 4), the drive electrodes COMLare so formed as to be extended along the same direction as that of thepixel signal lines SGL. Instead of this, the drive electrodes COML areso formed as to be extended along a direction intersecting with thepixel signal lines SGL in the present comparative example. That is, thedisplay device 1R is configured with use of a display unit 20R in whichthe drive electrodes COML are formed in this manner. The otherconfiguration is the same as that of the present embodiment (FIG. 1).

FIG. 10 shows a configuration example of the pixel structure in thedisplay unit 20R. As shown in FIG. 10, in the display unit 20R, thedrive electrodes COML are so formed as to be extended along a directionintersecting with the pixel signal lines SGL and the sub-pixel SPix isconnected to the other sub-pixels SPix that belong to the same row ofthe display unit 20R by the drive electrode COML. That is, the pluralsub-pixels SPix that belong to the same one row share one driveelectrode COML.

FIG. 11 schematically shows mounting of the display device 1R into adisplay module 5R. The display module 5R has the display unit 20R, driveelectrode drivers 16RA and 16RB, and a COG 19R. In the display unit 20Raccording to the present comparative example, the drive electrodes COMLare so formed as to be extended along a direction intersecting with thepixel signal lines SGL as schematically shown in FIG. 11. The driveelectrode drivers 16RA and 16RB (hereinafter, referred to also as driveelectrode drivers 16R collectively) are equivalent to the driveelectrode driver 16 shown in FIG. 1 and are so configured as to applythe drive signal Vcom to the drive electrode COML from both sides of thedisplay unit 20R. The COG 19R includes the respective circuits used fordisplay operation, such as the controller 11, the source driver 13, andthe drive signal generator 15 shown in FIG. 1. Specifically, in thedisplay device 1 according to the present embodiment (FIG. 6A), thedrive electrode driver 16 is formed in the COG 19. In contrast, in thedisplay device 1R according to the present comparative example (FIG.11), the drive electrode drivers 16R are formed not in the COG 19R buton the TFT substrate 21 on both sides of the display unit 20R in orderto connect the drive electrode drivers 16R to the drive electrodes COMLacross a short distance.

(Crosstalk Noise)

In the display device 1R, the drive signal Vcom is supplied from thesame drive electrode COML to each of the sub-pixels SPix in onehorizontal line that is selected by the scan signal Vscan and in whichthe pixel signal Vpix is written. That is, in the writing operation, thedrive signal Vcom is supplied to the respective sub-pixels SPix in thisone horizontal line via the common drive electrode COML. Thus, possiblynoise (crosstalk noise) is mixed from the other sub-pixels SPix in thisone horizontal line via the drive electrode COML. Details of thisphenomenon will be described below.

FIGS. 12A to 12D show timing waveform examples of the display device 1R.Specifically, FIG. 12A shows the waveform of the scan signal Vscan. FIG.12B shows the waveforms of the switch control signals VselR, VselG, andVselB. FIG. 12C shows the waveforms of the pixel signals VpixR, VpixG,and VpixB. FIG. 12D shows the waveform of the drive signal Vcom. Thetiming waveform examples of FIGS. 12A to 12D correspond to operation ofwriting the pixel signals Vpix (VpixR, VpixG, VpixB) to one horizontalline relating to the pixels Pix on the n-th row of the display unit 20R.

In the display device 1R, at timing t11, the drive signal generator 15and the drive electrode drivers 16R invert the drive signal Vcom(n)relating to the pixels Pix on the n-th row to set it to the low voltagelevel (FIG. 12D). Thereafter, during the period from timing t12 totiming t16, the gate driver 12 sets the scan signal Vscan(n) relating tothe pixels Pix on the n-th row to the high level to thereby select onehorizontal line in which writing operation is carried out (FIG. 12A). Inthis period, the source driver 13 and the selection switch unit 14sequentially apply the pixel signals VpixR, VpixG, and VpixB to thepixel signal line SGL. In this example, the pixel signal VpixR changesto a high voltage level simultaneously with turning of the switchcontrol signal VselR to the high level and the pixel signal VpixBchanges to a high voltage level simultaneously with turning of theswitch control signal VselB to the high level. On the other hand, thepixel signal VpixG changes to a slightly high voltage levelsimultaneously with turning of the switch control signal VselG to thehigh level. That is, the potential difference between the pixel signalVpix (VpixR, VpixG, VpixB) and the drive signal Vcom (pixel potential)is large in the sub-pixels SPix of red (R) and blue (B) and is small inthe sub-pixel SPix of green (G). For example if the display unit 20R isthe normally-black type, this state means that lighting with highluminance is obtained from the sub-pixels SPix of red (R) and blue (B)and lighting with low luminance is obtained from the sub-pixel SPix ofgreen (G).

As shown in FIG. 12D, the drive signal Vcom includes a large amount ofnoise superimposed on the original AC rectangular waveform like thatshown in FIG. 7A. For example, at the timings t12 and t16, thetransition of the scan signal Vscan(n) appears as noise in the drivesignal Vcom via parasitic capacitance between the scan signal line SGLand the drive electrode COML. Furthermore, in the period from the timingt13 to the timing t16, the transition of the pixel signal Vpix(particularly pixel signals VpixR and VpixB) is propagated from thepixel electrode 22 to the drive electrode COML via the capacitances Clcand Cs for example, and appears as noise in the drive signal Vcom.

Due to the influence of this noise, the drive signal Vcom(n) is not atits originally-designed voltage (−Vc) in the period from the timing t14to the timing t15. Specifically, the voltage level of the drive signalVcom(n) is somewhat higher than the originally-designed voltage (−Vc)(waveform part W1) due to the influence of the transition of the pixelsignal VpixR in the period from the timing t13 to the timing t14.Therefore, although the pixel signal VpixG is applied in this period,insufficiency of the writing occurs and the luminance of the sub-pixelSPix of green (G) is lower than the desired value. As just described, ifwriting is performed through application of the pixel signal Vpix whenthe voltage level of the drive signal Vcom deviates from theoriginally-designed voltage, the luminance of this sub-pixel SPixdeviates from the desired value.

In the display device 1R, the drive electrodes COML are so formed as tobe extended along a direction intersecting with the pixel signal linesSGL and the drive signal Vcom is supplied from the same drive electrodeCOML to each of the sub-pixels SPix in one horizontal line in whichwriting operation is carried out. This causes a possibility that, in thewriting operation, noise is mixed from the other sub-pixels SPix in thisone horizontal line via the drive electrode COML and the luminancedeviates from the desired value. That is, in the display device 1R,possibly the occurrence of this crosstalk noise leads to the lowering ofthe image quality.

In contrast, in the display device 1 according to the presentembodiment, the drive electrodes COML are so formed as to be extendedalong the same direction as that of the pixel signal lines SGL and thedrive signal Vcom is supplied from each of the different driveelectrodes COML to a respective one of the sub-pixels SPix in onehorizontal line in which writing operation is carried out. This canreduce the possibility that, in the writing operation, noise is mixedfrom the other sub-pixels SPix in this one horizontal line via the driveelectrode COML, and thus can suppress the lowering of the image qualitydue to crosstalk noise.

(Load of Drive Electrode Driver 16R)

The load of the drive electrode driver 16R in the present comparativeexample will be described below.

FIGS. 13A and 13B show the equivalent circuit of the display unit 20Raccording to the comparative example. Specifically, FIG. 13A shows thecase in which the TFT elements Tr are in the off-state. FIG. 13B showsthe case in which the TFT elements Tr are in the on-state.

The load from the viewpoint of the drive electrode COML in eachsub-pixel SPix is the same as that in the display device 1 of thepresent embodiment (FIGS. 9A and 9B). Specifically, when the TFT elementTr is in the off-state (writing operation is not carried out), as shownin FIG. 13A, this load is series capacitance made with parallelcapacitance (Clc+Cs) of the capacitive elements Clc and Cs and thecapacitive element Cds, and thus is a light capacitive load almost equalto the capacitance Cds. When the TFT element Tr is in the on-state(writing operation is carried out), this load is a heavy capacitive loadalmost equal to the capacitance (Clc+Cs) as shown in FIG. 13B.

However, in the display device 1R, the drive electrodes COML are soformed as to be extended along a direction intersecting with the pixelsignal lines SGL differently from the display device 1. Therefore, inthe rows in which writing operation is not carried out, writing iscarried out in none of all the sub-pixels SPix connected to therespective drive electrodes COML. In the row in which writing operationis carried out, writing is carried out in all the sub-pixels SPixconnected to the corresponding drive electrode COML. Specifically, asshown in FIG. 13A, the total load of the drive electrode COML relatingto the row in which writing is not performed in the display unit 20R isthe sum of the light capacitive loads of all the sub-pixels SPix thatbelong to this row. In contrast, as shown in FIG. 13B, the total load ofthe drive electrode COML relating to the row in which writing isperformed in the display unit 20R is the sum of the heavy capacitiveloads of all the sub-pixels SPix that belong to this row. That is, thetotal load of the drive electrode COML greatly differs depending onwhether or not writing is performed. In particular, the total load is avery large capacitive load when writing is performed. The driveelectrode driver 16R needs to be so configured as to be capable ofdriving this very large capacitive load when writing is performed, andtherefore possibly the circuit area and the power consumption increasein order to realize strong driving force.

Furthermore, in the display device 1R, as shown in FIG. 11, the driveelectrode drivers 16R are disposed at positions distant from the COG19R, in which the drive signal generator 15 is formed, and the terminalpart T, to which power is supplied. Therefore, the output impedance ofthe drive electrode driver 16R increases due to the time constant of theinterconnects for connecting these units, and possibly the driving forceof the drive electrode driver 16R is limited.

In contrast, in the display device 1 according to the presentembodiment, the drive electrodes COML are so formed as to be extendedalong the same direction as that of the pixel signal lines SGL.Therefore, always writing is performed in only one sub-pixel SPix of thesub-pixels SPix connected to a respective one of the drive electrodesCOML. Thus, the total load of the drive electrode COML in the displayunit 20 does not change depending on whether or not writing is performedand is the sum of the heavy capacitive load of one sub-pixel SPix inwhich the writing operation is carried out and the light capacitiveloads of the other sub-pixels SPix. That is, the load of the driveelectrode COML is smaller than that in the display device 1R. Therefore,the drive electrode driver 16 does not need strong driving forceequivalent to that in the display device 1R, so that increases in thecircuit area and the power consumption can be suppressed.

Furthermore, in the display device 1 according to the presentembodiment, as shown in FIGS. 6A and 6B, the drive electrode driver 16is formed in the COG 19 together with the drive signal generator 15 andcan be disposed at a position close to the terminal part T, to whichpower is supplied. Thus, the length of the interconnects for connectingthese units can be set short and the lowering of the driving force ofthe drive electrode driver 16 can be suppressed.

FIGS. 14A and 14B show results of simulation about the capability ofwriting to the pixel in the display device 1 according to the presentembodiment and the display device 1R according to the presentcomparative example. In the simulation of FIGS. 14A and 14B, thereaching time from application of the pixel signal Vpix to the pixelsignal line SGL by the source driver 13 and the selection switch unit 14to the timing when the potential difference between the pixel signalVpix and the drive signal Vcom (pixel potential) in a certain sub-pixelSPix reaches a predetermined potential is used as the index forevaluating the writing capability. FIG. 14A shows the reaching time ofthe pixel potential in the sub-pixel SPix close to the drive electrodedriver 16. FIG. 14B shows the reaching time of the pixel potential inthe sub-pixel SPix around the center of the display surface. In thisexample, the display device 1 according to the present embodiment has aconfiguration like that shown in FIG. 6B and the drive electrode COML isdriven from both sides of the display unit 20. That is, FIG. 14A showsthe data of the sub-pixel SPix in which the reaching time is theshortest. FIG. 14B shows the data of the sub-pixel SPix in which thereaching time is the longest.

As shown in FIGS. 14A and 14B, the reaching time in the display device 1according to the present embodiment is half that in the display device1R according to the present comparative example. That is, in the displaydevice 1 (FIG. 6B), the reaching time is shorter although the driveelectrode COML is longer compared with the display device 1R (FIG. 11).This is because of the following reasons. Specifically, as describedabove, in the display device 1, the total load from the viewpoint of thedrive electrode COML is lighter compared with the display device 1R andthe respective distances among the drive electrode driver 16, the drivesignal generator 15, and the terminal part T are shorter compared withthe display device 1R. Due to these features, in the display device 1,driving of the drive electrode COML by the drive electrode driver 16 isfacilitated and the reaching time can be shortened.

Advantageous Effects

As described above, in the present embodiment, the drive electrodes COMLare so formed as to be extended along the same direction as that of thepixel signal lines SGL and the drive signal Vcom is supplied from eachof the different drive electrodes COML to a respective one of thesub-pixels SPix in one horizontal line in which writing is performed.This can reduce the possibility that noise is mixed from the othersub-pixels SPix in this one horizontal line via the drive electrode COMLand can suppress the deterioration of the image quality.

Furthermore, in the present embodiment, writing is performed for onlyone sub-pixel SPix of the plural sub-pixels SPix connected to arespective one of the drive electrodes COML. Thus, the capacitive loadcomponent of the display unit from the viewpoint of the drive electrodeCOML can be set small and driving of the drive electrode COML by thedrive electrode driver can be facilitated.

In addition, in the present embodiment, the drive electrode driver isdisposed at a position close to the display unit, the drive signalgenerator, and the terminal part T. Thus, the time constant of theinterconnects among these units can be set small and driving of thedrive electrode COML by the drive electrode driver can be facilitated.

[Modification Example 1-1]

In the above-described embodiment, the respective drive electrodes COMLare each directly connected to the drive electrode driver 16 via thedrive electrode line part 29. However, the configuration is not limitedthereto. Instead of this, the drive electrodes COML may be connected tothe drive electrode driver 16 via a switch as shown in FIG. 15 forexample. In the example of FIG. 15, this switch (drive electrode switchSWCOM) is composed of three switches. One terminals of these switchesare connected to each other and supplied with the drive signal Vcom fromthe drive electrode driver 16 and the other terminals are connected tothe drive electrodes COML of the display unit 20. In this example, forexample three switches in each drive electrode switch SWCOM aresequentially turned to the on-state in a time-division manner, andthereby the drive electrode driver 16 can supply the drive signal Vcomto each of the drive electrodes COML.

Modification Example 1-2

In the above-described embodiment, the drive signal Vcom is supplied inunits of the sub-pixel SPix. However, the configuration is not limitedthereto. Instead of this, the drive signal Vcom may be supplied in unitsof the plural sub-pixels SPix for example. Several examples will bedescribed below.

FIGS. 16A and 16B show configuration examples when the drive signal Vcomis supplied in units of the pixel Pix. FIG. 16A shows a configurationexample in which, of the drive electrodes COML formed on each sub-pixelSPix basis, three drive electrodes COML relating to the same pixel Pixare connected to each other (drive electrode line part 29B) andconnected to the drive electrode driver 16. FIG. 16B shows aconfiguration example in which the drive electrodes COML eachcorresponding to the width of the pixel Pix (three sub-pixels SPix) areformed and connected to the drive electrode driver 16 via a driveelectrode line part 29C. These configurations allow the drive electrodedriver 16 to supply the drive signal Vcom in units of the pixel Pix. Inthis case, the dot-inversion driving for the display unit 20 is not thesub-pixel-inversion driving, in which the polarity is inverted on eachsub-pixel SPix basis, described for the above-described embodiment butpixel-inversion driving in which the polarity is inverted on each pixelPix basis.

FIG. 17 shows one configuration example when the drive signal Vcom issupplied in units of two pixels Pix. The drive electrodes COML eachcorresponding to the width of two pixels Pix are formed and connected tothe drive electrode driver 16 via a drive electrode line part 29D. Thisconfiguration allows the drive electrode driver 16 to supply the drivesignal Vcom in units of two pixels Pix. In this case, the driving methodfor the display unit 20 is inversion driving in which the polarity isinverted every two pixels Pix.

Modification Example 1-3

In the above-described embodiment, the display unit 20 is driven basedon the dot-inversion driving. However, the configuration is not limitedthereto. Instead of this, the display unit 20 may be driven based onso-called line-inversion driving like that shown in FIGS. 18A and 18Bfor example. In FIGS. 18A and 18B, FIG. 18A shows the polarities of thepixel potentials for the sub-pixels SPix in a certain frame. FIG. 18Bshows the polarities of the pixel potentials in the next frame. As shownin FIGS. 18A and 18B, in the line-inversion driving, the display unit 20is so driven that, in a certain frame, the polarities of the pixelpotentials of the sub-pixels SPix adjacent to each other along the rowdirection are identical to each other and the polarities of the pixelpotentials of the sub-pixels SPix adjacent to each other along thecolumn direction are different from each other. Furthermore, thepolarities of the pixel potentials of all of the sub-pixels SPix areinverted on a frame-by-frame basis.

[Other Modification Examples]

In the above-described embodiment, the pixel signal Vsig is configuredby time-division multiplexing of the pixel signals Vpix of threesub-pixels SPix. However, the configuration is not limited thereto.Instead of this, the pixel signals Vpix of four or more sub-pixels SPixor two sub-pixels SPix may be subjected to the time-divisionmultiplexing for example. In this case, the number of switches in eachswitch group 17 of the selection switch unit 14 is set equal to thenumber of sub-pixels SPix as the multiplexing subject.

In the above-described embodiment, the source driver 13 supplies thepixel signal Vsig to the selection switch unit 14 and the selectionswitch unit 14 separates the pixel signals Vpix from the pixel signalVsig and supplies the pixel signals Vpix to the display unit 20.However, the configuration is not limited thereto. Instead of this, thesource driver may generate the pixel signals Vpix and supply themdirectly to the display unit 20 without the provision of the selectionswitch unit 14 for example.

2. APPLICATION EXAMPLES

With reference to FIG. 19 to FIG. 23G, application examples of thedisplay device described for the above-described embodiment andmodification examples will be described below. The display device of theabove-described embodiment and so forth can be applied to electronicapparatus in every field, such as a television device, a digital camera,a notebook personal computer, a portable terminal device typified by acellular phone, and a video camcorder. In other words, the displaydevice of the above-described embodiment and so forth can be applied toelectronic apparatus in every field that displays a video signal inputfrom the external or a video signal generated inside as image or video.

Application Example 1

FIG. 19 shows the appearance of a television device to which the displaydevice of the above-described embodiment and so forth is applied. Thistelevision device has e.g. a video display screen part 510 including afront panel 511 and a filter glass 512, and this video display screenpart 510 is formed of the display device according to theabove-described embodiment and so forth.

Application Example 2

FIGS. 20A and 20B show the appearance of a digital camera to which thedisplay device of the above-described embodiment and so forth isapplied. This digital camera has e.g. a light emitter 521 for flash, adisplay part 522, a menu switch 523, and a shutter button 524, and thisdisplay part 522 is formed of the display device according to theabove-described embodiment and so forth.

Application Example 3

FIG. 21 shows the appearance of a notebook personal computer to whichthe display device of the above-described embodiment and so forth isapplied. This notebook personal computer has e.g. a main body 531, akeyboard 532 for input operation for characters, etc., and a displaypart 533 that displays images, and this display part 533 is formed ofthe display device according to the above-described embodiment and soforth.

Application Example 4

FIG. 22 shows the appearance of a video camcorder to which the displaydevice of the above-described embodiment and so forth is applied. Thisvideo camcorder has e.g. a main body part 541, a lens 542 that isprovided on the front side of this main body part 541 and used forsubject photographing, a start/stop switch 543 used in photographing,and a display part 544. This display part 544 is formed of the displaydevice according to the above-described embodiment and so forth.

Application Example 5

FIGS. 23A to 23G show the appearance of a cellular phone to which thedisplay device of the above-described embodiment and so forth isapplied. For example, this cellular phone is formed by connecting anupper case 710 to a lower case 720 by a connecting part (hinge part) 730and has a display 740, a sub-display 750, a picture light 760, and acamera 770. The display 740 or the sub-display 750 is formed of thedisplay device according to the above-described embodiment and so forth.

The present disclosure has been described above by taking embodiment,modification examples, and examples of application to electronicapparatus. However, the present disclosure is not limited to theembodiment and so forth and various modifications are possible.

For example, in the above-described embodiment and so forth, the displayunit 20 is configured by using a liquid crystal of any of various kindsof modes such as TN, VA, and ECB modes. However, instead of this, aliquid crystal of a transverse electric field mode such as a fringefield switching (FFS) mode or an in-plane switching (IPS) mode may beused. For example, if a liquid crystal of the transverse electric fieldmode is used, a display unit 90 can be configured as shown in FIG. 24.FIG. 24 shows one example of the sectional structure of the major partof the display unit 90 and shows the state in which a liquid crystallayer 6B is interposed between a pixel substrate 2B and a countersubstrate 3B. The names, functions, and so forth of the other respectivecomponents are the same as those in FIG. 3 and therefore descriptionthereof is omitted. In this example, the drive electrode COML is formedjust on the TFT substrate 21 and forms part of the pixel substrate 2Bdifferently from the case of FIG. 3. The pixel electrode 22 is disposedover the drive electrode COML with the intermediary of an insulatinglayer 23.

For example, in the above-described embodiment and so forth, a liquidcrystal display element is used as the display element. However, theconfiguration is not limited thereto. Instead of this, any displayelement such as an electro luminescence (EL) element may be used.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2010-187222 filed in theJapan Patent Office on Aug. 24, 2010, the entire content of which ishereby incorporated by reference.

What is claimed is:
 1. A display device comprising: a plurality ofsignal lines configured to be so juxtaposed as to be extended along onedirection; a plurality of common drive electrodes configured to be sojuxtaposed as to be extended along the signal lines; and a plurality ofdisplay elements configured to be each connected to a respective one ofthe plurality of signal lines and be each connected also to the commondrive electrode that makes a pair with the connected signal line, scandriving of the plurality of display elements being performed indirection of the signal lines.
 2. The display device according to claim1, wherein a width of the common drive electrode corresponds to a widthof the display element.
 3. The display device according to claim 1,wherein the width of the common drive electrode corresponds to the widthof a predetermined number of the display elements, and the common driveelectrode is so formed as to make a pair with the predetermined numberof the signal lines.
 4. The display device according to claim 3, whereinthe predetermined number of display elements configure a display pixelincluding one red display element, one green display element, and oneblue display element.
 5. The display device according to claim 1,wherein the display element is a liquid crystal display element.
 6. Thedisplay device according to claim 1, further comprising: a driverconfigured to be disposed at a side intersecting with extendingdirection of the plurality of common drive electrodes and drive theplurality of common drive electrodes; and a terminal part configured tobe disposed at the side at which the driver is disposed and supply asignal to the driver.
 7. A display device comprising: a plurality ofsignal lines configured to be so juxtaposed as to be extended along afirst direction; a plurality of drive electrodes configured to be sojuxtaposed as to be extended along the first direction; and a pluralityof display elements configured to be subjected to scan driving in thefirst direction.
 8. The display device according to claim 7, furthercomprising: a terminal part configured to be supplied with power; adrive electrode driver configured to supply a drive signal to theplurality of drive electrodes; a plurality of scan signal linesconfigured to be so juxtaposed as to be extended along a seconddirection; and a gate driver configured to supply a scan signal to theplurality of scan signal lines, wherein the drive electrode driver isdisposed at a position closer to the terminal part than the gate driver.9. Electronic apparatus comprising: a display device; and a controllerconfigured to control operation carried out by utilizing the displaydevice, wherein the display device includes a plurality of signal linesthat are so juxtaposed as to be extended along one direction, aplurality of common drive electrodes that are so juxtaposed as to beextended along the signal lines, and a display element that is insertedand connected between the signal line and the common drive electrodethat make a pair with each other, and is subjected to scan driving indirection of the signal lines.